3-Fluoro-N-(3-fluoro­benzo­yl)-N-(2-pyrid­yl)benzamide

John F Gallagher; Katie Donnelly; Alan J Lough

doi:10.1107/S1600536808041093

. 2008 Dec 13;65(Pt 1):o102–o103. doi: 10.1107/S1600536808041093

3-Fluoro-N-(3-fluorobenzoyl)-N-(2-pyridyl)benzamide

John F Gallagher ^a,^*, Katie Donnelly ^a, Alan J Lough ^b,^‡

PMCID: PMC2968027 PMID: 21581566

Abstract

The title compound, C₁₉H₁₂F₂N₂O₂, a 2:1 product of the reaction of 3-fluorobenzoylchloride and 2-aminopyridine crystallizes with a disordered 3-fluorobenzene ring adopting two conformations [ratio of occupancies 0.959 (4):0.041 (4)]. In the crystal structure, there are no classical hydrogen bonds and interactions comprise C—H⋯O in the form 2(C—H)⋯O=C [with motif R ₂ ¹(5)]; C—H⋯π(arene) interactions are also present.

Related literature

For background information, see: Donnelly et al. (2008 ▶); Gallagher et al. (2008 ▶); McMahon et al. (2008 ▶); Moody et al. (1998 ▶). For a description of the Cambridge Structural Database, see: Allen (2002 ▶). For the parent compound, 2-(dibenzoylamino)pyridine, see: Weng et al. (2006 ▶). For related structures, see: Usman et al. (2002a ▶,b ▶).

Experimental

Crystal data

C₁₉H₁₂F₂N₂O₂
M _r = 338.31
Triclinic,
a = 5.4932 (4) Å
b = 8.1549 (5) Å
c = 17.9205 (15) Å
α = 78.081 (4)°
β = 89.588 (3)°
γ = 76.693 (3)°
V = 763.69 (10) Å³
Z = 2
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 150 (1) K
0.34 × 0.30 × 0.12 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1995 ▶) T _min = 0.873, T _max = 0.992
5197 measured reflections
3422 independent reflections
1966 reflections with I > 2σ(I)
R _int = 0.043

Refinement

R[F ² > 2σ(F ²)] = 0.057
wR(F ²) = 0.167
S = 1.04
3422 reflections
236 parameters
5 restraints
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Data collection: KappaCCD Server Software (Nonius, 1997 ▶); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997 ▶); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶) and SORTX (McArdle, 1995 ▶); molecular graphics: PLATON (Spek, 2003 ▶); software used to prepare material for publication: SHELXL97 and PREP8 (Ferguson, 1998 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808041093/tk2338sup1.cif

e-65-0o102-sup1.cif^{(18.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808041093/tk2338Isup2.hkl

e-65-0o102-Isup2.hkl^{(167.8KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C24—H24⋯O2ⁱ	0.95	2.53	3.097 (3)	119
C25—H25⋯O2ⁱ	0.95	2.46	3.063 (3)	121
C25—H25⋯Cg1ⁱ	0.95	2.79	3.606 (3)	145

Open in a new tab

Symmetry code: (i) Inline graphic . Cg1 is the centroid of the C11–C16 benzene ring.

Acknowledgments

JFG thanks Dublin City University for grants in aid of undergraduate research. Thanks especially to Mr Damien McGuirk for providing excellent technical support in the undergraduate research laboratories.

supplementary crystallographic information

Comment

Our group is completing a structural systematic study of fluoro-N'-(pyridyl)benzamide isomers (Donnelly et al., 2008) and we are adding to our research with the analogous difluoro-N-(pyridyl)benzamide series (McMahon et al., 2008) (Scheme 1).

In the chemical synthesis of either the mono- or di-fluoro derivatives and when using the ortho-aminopyridine, two products can be isolated as either the 1:1 or 2:1 benzoyl:pyridine components, and with yields and ratios depending on the reaction conditions. We have reported the structure of the 1:1 derivative, 2,3-difluoro-N-(2-pyridyl)benzamide (Gallagher et al., 2008), and now report a 2:1 relative of this compound, namely 3-fluoro-N'-(3-fluorobenzoyl)-N'-(2-pyridinyl)benzamide (I) (Figs 1 & 2). The parent compound 2-(dibenzoylamino)pyridine has been reported previously (Weng et al., 2006) as well as the compounds N,N-dibenzoyl-4-chloroaniline and 4-acetyl-N,N-dibenzoylphenylamine (Usman et al., 2002a,b).

In the crystal structure of (I), there are no classical hydrogen bonds and the weaker interactions present consist of C—H···O and C—H···π(arene) contacts. An unusual (phenyl)C—H···C=O interaction arises between neighbouring molecules as (C24—H24/C25—H25)···O2=C2ⁱ [graph set R₂¹(5)] with O···C distances of 3.062 (3) and 3.097 (3) Å (symmetry code: i = x - 1, y + 1, z), Table 1.

A search of the literature (Allen, 2002) reveals a structure exhibiting a comparable example of hydrogen bonding and is archived in the CSD (as XOXRIL). However, in this structure the interacting molecules are offset with respect to the C=O···C₂ moiety in the aromatic C₅N ring. A related search yielded POZWUW (Fig. 3) (Moody et al., 1998) and RINXUI which both have relatively symmetrical C=O···C₂ distances similar to (I) and form chains along the b axis. In the POZWUW structure the C3/C4···O1ⁱⁱ distances are 3.013 (3) and 3.090 (3) Å, and similar to that in (I) (symmetry code: ii = x, y - 1, z) (Fig. 3).

A related search for C=O···C₂ [in C₆] yielded 6 compounds in the same range of C···O from 2.0–3.0 Å but most were disordered, with high R-factors and typically had the solvent benzene as the acceptor; these are listed as BARJUZ10, LAYDAQ, MERRIK, OGOPUV, SEDLET, XICFEV (Allen, 2002).

Experimental

Compound (I) was synthesized via standard condensation procedures and similar to the related syntheses reported previously (Donnelly et al., 2008; McMahon et al., 2008). Separation of the 1:1 and 2:1 derivatives was undertaken by using flash chromatography. Typical organic workup and washing gave the product (I) in modest yield of 25–35% as a 2:1 component of the mixture. Crystals suitable for X-ray diffraction were grown from CHCl₃ as colourless blocks over a period of 1–2 weeks and gave a melting point of 401–406 K. The compounds gave clean ¹H and ¹³C NMR spectra in CDC₃ and infrared spectra (in CHCl₃ solution, and as KBr disks).

For (I), m.p. 401–406 K (uncorrected). IR (ν_C=O cm^-1): 1697(s, br), (CHCl₃); 1695(s) (KBr).